Custom Search
|
|
|
||
 LANTNAVFACENGCOM A&E GUIDE
3/93
When large loads or many small loads of this type are served, the waveshape
of the load current is badly distorted and high in harmonics. This results in
overheating of neutral conductors, intermittent electrical noise, transformer
overheating, and convertor failure.
Therefore, when dealing with non-linear loads, it is imperative that the
designer obtain accurate load information and precisely design system
components based on the load information obtained.
A.1.15
HAZARDOUS (CLASSIFIED) LOCATIONS
Define in accordance with NFPA 70, "National Electrical Code." Clearly
show boundaries of hazardous locations on the plans and identify the type of
hazard by class, division, and group.
A.2
ELECTRICAL SYSTEMS
A.2.1
UNDERGROUND ELECTRICAL SYSTEMS
GENERAL GUIDANCE
A.2.1.1
a. MIL-HDBK-1004/1, "Preliminary Design Considerations," MIL-HDBK-
1004/2, "Power Distribution Systems," and NFGS-16375, "Underground
Electrical Work."
b. For the purposes of this guide, an underground conduit or duct run
consisting of a single conduit or duct shall be defined as a conduit run;
an underground conduit or duct run consisting of two or more conduits
or ducts shall be defined as a ductbank or duct run.
A.2.1.2
MANHOLES (MH'S) AND HANDHOLES (HH'S)
a. Avoid use of combination power and communication manholes;
however, when power and communication duct lines follow the same
route use a common trench and locate power and communication
manholes in close proximity to one another. Use manholes for main
duct runs and wherever shielded medium-voltage cable is installed.
Handholes may be used for airfield lighting circuits. for other
nonshielded medium-voltage circuits, and on building laterals for low-
voltage and communication lines.
b. Size of manholes and handholes should be determined by number of
circuits and by voltage ratings and splicing requirements of the cables
Attachment A-10
|
 
|
|
|
||
